Hydraulic system



July 10, 1934. J. M. 'TOWLER 1,966,421

HYDRAULIC SYSTEM Fiied Dec. 15, 19:53

@mm Q A TTORNEY Patented July 10, 1934 UNITED STATES PATENT F FICE 1,966,421 HYDRAULIC SYSTEM John Maurice Towler, Summer Bridge, Yorkshire, England Application December 13,

1933, Serial No. 702,233

This invention relates to hammers, presses and hydraulic systems and particularly to such systems supplying pressure fluid to forging presses or like apparatus-in which the ram of the press moves against a very variable resist- I ance, so that the average power exerted is only a fraction of the maximum power, and further in which the press ram has to be operated at a very high speed against maximum load to avoid the excessive cooling of the work, or for other causes. One of the objects of the present invention is to provide means whereby practically the whole kinetic energy of the moving parts of a press working at high speed can be converted into useful work without appreciable shock to the foundations.

A further object of the invention is to provide a hydraulic apparatus which may be controlled with a minimum of valve gear.

, In order that the invention may be clearly understood and carried into effect an embodiment of thesame will now be described by aid of the accompanying diagrammatic drawing.

In the drawing is illustrated a hydraulic press or hammer comprising an upper stationary anvil a and a lower movable tup b with which is associated a press ram 0 working within a cylinder 12. Liquid under pressure is supplied to the under side of the ram 0 from a common chamber e through a connection f, said liquidbeing compressed within said chamber by the inward movement of a pair of opposed intensifier rams g.

On the outer end of each of these intensifier rams is mounted a piston h which slides within cylinders i, said cylinders being closed at both ends. The inner ends of the two cylinders are connected together by piping k and to a conventional source of intermittent fluid pressure to which no claim is made per se, which may comprise a pump a and operating valve 0, the pump serving to force liquid under presure simultaneously into the two cylinders on the inner sides of the pistons for the purpose of forcing said pistons outwards. Air under pressure is maintained within the outer ends of the cylinders and such ends are coupled together by piping Z forming a closed circuit which may include the storage chamber m.

On the outward movement or storing stroke of the pistons h by the aforesaid pressure liquid, the air within the outer ends of the cylinders be-' comes highly compressed. Upon the release of the pressure liquid from within the inner ends of the cylinders by the opening of an operating valve 0, such highly compressed air expands and forces the two intensifier rams simultaneously inwards throughout their working stroke, thus forcing the liquid within the common chamber e into the cylinder d of the press ram and thereby imparting 0 a working stroke to the tup b, the work p to be operated on being interposed between said tup and the stationary anvil (1.

So that no appreciable shock shall be transmitted to the foundations of the apparatus, it 5 is essential that the momenta of the two intensifier rams be equal and balance out or neutralize I each other.

In the example illustrated in the present application, this is assured by making the two intensifier rams with their associated pistons of equal diameter and weight and, in consequence of the balancing pipe I which insures that equal pressure is applied to both pistons, such rams will move inwardly with equal velocities and consequently equal momenta. In practice, it is always preferred to make such masses of equal weight and diameter as aforesaid whereby the same can be caused to move in opposition to each other with equal velocities.

However, within the scope of the present invention, rams and pistons associated therewith of different weights may be utilized.

It will of course be understood that more than two intensifier rams may be employed provided that their momenta are equal and opposite so as to balance out or neutralize each other.

It is not-my intention to limit myself to the illustrative example of my invention disclosed herein, but to include such forms and modifications as may fall within the scope-of the appended claims.

What I claim is:

1. In a hydraulic apparatus, the combination with a press ram of means for supplying pressure fluid thereto, said means comprising a plurality of opposed intensifier rams movable in cylinders,

a common chamber between the inner ends of said intensifier ram cylinders, a press ram cylinder, a connection between said chamber and said press ram cylinder, a piston associated with each intensifier ram and movable therewith in said cylinders, a connection between the outer ends of said cylinders including pressure storage means, and a connection between the inner ends of said cylinders and a source of intermittent fluid pressure, said connections being so arranged that equal pressures are exerted on the several pistons during their actuation.

2. In a hydraulic apparatus, the combination n with a press ram 01 means for developing hydraulic pressure for the operation thereoi, said plurality of intensifier rams, the innerends of means comprising a a common chamber between said intensifier rams, a press ram cylinder, a-

connection between said chamber and said press to actuate said intensifier rams throughout a storing stroke, said last means comprising a connection between the inner ends of said cylinders and with a source or intermittent pressure, whereby pressure is exerted intermittently on said pistons to actuate said rams in unison, and a pressure storage connection between the outer ends of said cylinders for storing a compressible fluid which is compressed by said pistons during the storing stroke of said intensifier rams.

3. In a hydraulic apparatus, the combination with a press ram 01 means for developinghydraulic pressure for the operation thereof, said means comprising a plurality of intensifier rams movable in opposition, a common chamber between the inner ends of said intensifier rams, a press ram cylinder, and a connection between the chamber and said press ram cylinder, a piston associated with each of said intensifier rams, cylinders for said pistons, and means to actuate in unison said intensifier rams throughout their working stroke, such means comprising a pressure storage connection between the outer ends of said cylinders for storing a compressible medium operative against the outer sides of said pistons, means for connecting the inner ends 0t said cylinders with a source of intermittent pressure operative against the inner sides of said pistons to actuate intermittently and in unison said pistons whereby to compress the compressible medium, and means for releasing intermittently the pressure from the inner ends 01 said cylinders, whereby expansion of the compressed,

compressible medium actuates said pistons and intensifier rams to develop pressure in said common chamber.

4. In a hydraulic apparatus, the combination of a press ram, -a plurality of intensifier rams adapted to supply pressure fluid tor the opera.- tion of said press ram, a closed cylinder and a piston therein associated with each intensifier ram, a pressure storage connection between the outer ends of said cylinder and operative to store whereby the expanding compressible medium actuates said intensifier rams in unison to develop pressure for operating the press ram, both said connections being so arranged that equal pressures are exerted on the several pistons during their actuation.

5. In a hydraulic apparatus, the combination with a press ram of means for supplying pressure thereto, said means comprising a plurality of intensifier rams movable in cylinders in opposition to each other, a piston associated with each of said intensifier rams and movable therewith in said cylinders, -means for actuating intermittently and in unison said rams and associated pistons throughout a storing stroke, and means for actuating in unison said rams and associated pistons throughout a working stroke, said lastnamed means comprising a pressure storage connection between the outer ends of said cylinders for storing fluid under pressure, said con-, nection being so arranged that equal are exerted at all times upon the outer sides of the several pistons.

JOHN MAURICE TOWLER.

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